Potential of interferometric cantilever detection and its application for SFM/AFM in liquids

We have developed an optical cantilever deflection detector with a spot size <3 µm and fm Hz(-1/2) sensitivity over a>10 MHz bandwidth. In this work, we demonstrate its potential for detecting small-amplitude oscillations of various flexural and torsional oscillation modes of cantilevers. The high deflection sensitivity of the interferometer is particularly useful for detecting cantilever oscillations in aqueous solutions, enabling us to reach the thermal noise limit in scanning or atomic force microscopy experiments with stiff cantilevers. This has resulted in atomic-resolution images of solid-liquid interfaces and submolecular-resolution images of native membranes.

Fluctuation theorem for entropy production during effusion of a relativistic ideal gas

The probability distribution of the entropy production for the effusion of a relativistic ideal gas is calculated explicitly. This result is then extended to include particle and antiparticle pair production and annihilation. In both cases, the fluctuation theorem is verified.

Candida prosthetic valve endocarditis: the complementary role of multidetector computed tomography and transoesophageal echocardiography in preoperative evaluation

A 72-year-old man with previous mitral valve replacement and single coronary bypass surgery was diagnosed with recurrent candida endocarditis by transoesophageal echocardiography and positive blood cultures. Preoperative electrocardiogram-gated multidetector CT (MDCT) was ordered to evaluate the patency and course of the mammary graft. In addition to verifying graft patency, MDCT demonstrated a mobile vegetation on the mitral prosthesis as well as a vegetation on the posterior left atrial wall which was not visible by transoesophageal echocardiography. Multidetector CT also revealed signs of osteomyelitis in the thoracic spine. Repeated surgery confirmed these findings and mitral valve replacement with resection of the left atrial vegetation were performed. This case illustrates the complementary role of MDCT and echocardiography in the preoperative evaluation of fungal endocarditis.

Left ventricular pseudoaneurysm or diverticulum: differential diagnosis and dynamic evaluation by catheter left ventriculography and ECG-gated multidetector CT

We present a case report of the findings of a left ventricular diastolic out pouching in a patient following acute myocardial infarction diagnosed by catheter left ventriculography and electrocardiography (ECG)-gated multidetector computed tomography (MDCT) findings. Left ventriculography demonstrated a small left ventricular diastolic out pouching, while MDCT enabled accurate evaluation of both left ventricular myocardium and lumen, establishing the diagnosis of an intramural small left ventricular pseudoaneurysm. This case illustrates the full capabilities of MDCT in the evaluation of left ventricular pseudoaneurysms.

CT scout view as an essential part of CT reading

Computed tomography scout view is a mode of operating a CT system. It is generally used to prescribe CT slices and to display slice locations rather than for direct diagnosis. However, we found that a careful study of CT scout view can contribute significantly to the diagnosis. We show seven abdominal, two chest and two head CT, where the study of CT scout view allowed diagnoses to be made that were not readily apparent from the axial slices.

[Pancreatic carcinoma?]

We report the case of a 71 years old man suspected to suffer from pancreatic carcinoma because of a large mass in the pancreatic head. Intraoperatively, this suspicion could not be confirmed. An unspecific pancreatitis was found. Despite gastrojejunostomy and cholecystectomy with biliodigestive anastomosis and Y-Roux abdominal pain and a massive lost of weight persisted. In the course, the diagnosis of an autoimmune pancreatitis was maid and symptoms quickly improved after the introduction of corticosteroids. In the commentary of this paper the issue of autoimmune pancreatitis will be discussed.

Zaspopathy in a large classic late-onset distal myopathy family

Distal myopathies have been associated with mutations in titin, dysferlin, GNE, desmin and myosin. Of these, only titin mutations were previously known to cause dominant late-onset distal myopathy. Recent findings, however, have indicated that patients affected with myofibrillar myopathy have a more distal than proximal muscle phenotype and a proportion of these may have mutations in myotilin, ZASP or filamin C, besides previously known desmin and alphaB-crystallin. Here we report that the disorder in one of the well-characterized autosomal dominant distal myopathy families, the Markesbery et al. family, first reported in 1974, is caused by ZASP mutation A165V. Previous linkage to the titin locus 2q31 proved incorrect. ZASP expression by immunoblotting shows normal presence of the main 32 and 78 kDa bands and immunohistochemistry in patients reveals normal Z-disc localization except for moderate accumulations together with myotilin, desmin alphaB-crystallin and alpha-actinin. Muscle imaging reveals involvement in both the posterior and anterior compartments of the lower leg and considerable affection of proximal leg muscles at later stages. Haplotype studies in this family and in five other unrelated families with European ancestry carrying the identical A165V mutation share common markers at the locus suggesting the existence of a founder mutation.

Comprehensive multidetector CT assessment of apical hypertrophic cardiomyopathy

16-slice multidetector CT (MDCT) cardiac findings of a middle-aged man with known apical hypertrophic cardiomyopathy (AHC) and recent atypical chest pain are presented. MDCT enabled comprehensive evaluation of the coronary arteries, diagnosing myocardial bridging of the left anterior descending (LAD) and first diagonal arteries. It also enabled dynamic evaluation of myocardial thickness and left ventricular global and regional function. This case illustrates the full capabilities of MDCT in the evaluation of AHC.

The Golgi-resident protease Kex2 acts in conjunction with Prm1 to facilitate cell fusion during yeast mating

The molecular machines that mediate cell fusion are unknown. Previously, we identified a multispanning transmembrane protein, Prm1 (pheromone-regulated membrane protein 1), that acts during yeast mating (Heiman, M.G., and P. Walter. 2000. J. Cell Biol. 151:719-730). Without Prm1, a substantial fraction of mating pairs arrest with their plasma membranes tightly apposed yet unfused. In this study, we show that lack of the Golgi-resident protease Kex2 strongly enhances the cell fusion defect of Prm1-deficient mating pairs and causes a mild fusion defect in otherwise wild-type mating pairs. Lack of the Kex1 protease but not the Ste13 protease results in similar defects. Deltakex2 and Deltakex1 fusion defects were suppressed by osmotic support, a trait shared with mutants defective in cell wall remodeling. In contrast, other cell wall mutants do not enhance the Deltaprm1 fusion defect. Electron microscopy of Deltakex2-derived mating pairs revealed novel extracellular blebs at presumptive sites of fusion. Kex2 and Kex1 may promote cell fusion by proteolytically processing substrates that act in parallel to Prm1 as an alternative fusion machine, as cell wall components, or both.

Influence of high tibial osteotomy on bone marrow edema in the knee

To determine the influence of high tibial osteotomy on subchondral bone marrow edema in medial osteoarthritis of the varus knee, full leg-length radiographs and magnetic resonance imaging were performed in 20 patients (20 knees) before surgery, 1 year postoperatively, and at a mean of 7 years postoperatively. The extent of bone marrow edema in the medial compartment was quantified with magnetic resonance imaging in two planes using the formula for a prolate ellipsoid as follows: length x width x depth x pi/6. We used the Japanese Orthopaedic Association knee score for clinical evaluation. At the last followup, all knees with valgus alignment (10/10) showed reduced edema. In contrast, bone marrow edema increased or remained unchanged in four of 10 knees with neutral or varus alignment. The percentage of satisfactory results was 100% (10/10) in valgus knees and only 30% (3/10) in neutral or varus knees. Extent of bone marrow edema at the followup correlated with the mechanical axis and knee score. Because of the prognostic value of bone marrow abnormalities in the medial compartment observed on magnetic resonance imaging, early lateral closing wedge osteotomy should be considered in patients with varus malalignment and bone marrow edema even in mild cases of medial osteoarthritis.

The plasma membrane proteins Prm1 and Fig1 ascertain fidelity of membrane fusion during yeast mating

As for most cell-cell fusion events, the molecular details of membrane fusion during yeast mating are poorly understood. The multipass membrane protein Prm1 is the only known component that acts at the step of bilayer fusion. In its absence, mutant mating pairs lyse or arrest in the mating reaction with tightly apposed plasma membranes. We show that deletion of FIG 1, which controls pheromone-induced Ca(2+) influx, yields similar cell fusion defects. Although extracellular Ca(2+) is not required for efficient cell fusion of wild-type cells, cell fusion in prm1 mutant mating pairs is dramatically reduced when Ca(2+) is removed. This enhanced fusion defect is due to lysis. Time-lapse microscopy reveals that fusion and lysis events initiate with identical kinetics, suggesting that both outcomes result from engagement of the fusion machinery. The yeast synaptotagmin orthologue and Ca(2+) binding protein Tcb3 has a role in reducing lysis of prm1 mutants, which opens the possibility that the observed role of Ca(2+) is to engage a wound repair mechanism. Thus, our results suggest that Prm1 and Fig1 have a role in enhancing membrane fusion and maintaining its fidelity. Their absence results in frequent mating pair lysis, which is counteracted by Ca(2+)-dependent membrane repair.

Cilostamide potentiates more the positive inotropic effects of (-)-adrenaline through beta(2)-adrenoceptors than the effects of (-)-noradrenaline through beta (1)-adrenoceptors in human atrial myocardium

Activation of both beta(1)- and beta(2)-adrenoceptors increases the contractility of human atrial myocardium through cyclic AMP-dependent pathways. Cyclic AMP is hydrolised by phosphodiesterases, but little is known about which isoenzymes catalyse inotropically relevant cyclic AMP accumulated upon stimulation of beta-adrenoceptor subtypes. We have compared the positive inotropic effects of (-)-noradrenaline and (-)-adrenaline, mediated through beta(1)- and beta(2)-adrenoceptors, respectively, in the absence and presence of the PDE3 inhibitor cilostamide (300 nM) or PDE4 inhibitor rolipram (1 muM) on human atrial trabeculae from non-failing hearts. Cilostamide, but not rolipram, potentiated the effects of both (-)-noradrenaline and (-)-adrenaline. Cilostamide increased the -logEC(50)M of (-)-adrenaline more than of (-)-noradrenaline (P < 0.05), regardless of whether or not the patients had been chronically treated with beta-blockers. The results are consistent with a greater PDE3-catalysed hydrolysis of inotropically relevant cyclic AMP produced through beta(2)-adrenoceptors than beta(1)-adrenoceptors in human atrium.

The influence of propofol on the expression of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) in reoxygenated human umbilical vein endothelial cells

BACKGROUND

Leucocytes are a pivotal component of the inflammatory cascade that results in tissue injury in a large group of disorders. Free radical production and endothelial activation promote leucocyte-endothelium interactions via endothelial expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1) which augment these processes, particularly in the setting of reperfusion injury. Propofol has antioxidant properties which may attenuate the increased expression of these molecules that is observed.

METHODS

Cultured human umbilical vein endothelial cells were exposed to 20 h of hypoxia, then returned to normoxic conditions. Cells were treated with saline, Diprivan 5 microg mL(-1) or propofol 5 microg mL(-1), for 4 h after reoxygenation and were examined for ICAM-1 and VCAM-1 expression.

RESULTS

Hypoxia did not increase the expression of ICAM-1/VCAM-1. ICAM-1 expression peaked 12 h after reoxygenation (21.75(0.6) vs. 9.6(1.3), P = 0.02). Propofol, but not Diprivan, prevented this increase (8.2(2.9) vs. 21.75(0.6), P = 0.009). VCAM-1 expression peaked 24 h after reoxygenation (9.8(0.9) vs. 6.6(0.6), P = 0.03). Propofol and Diprivan prevented this increase, with no difference between the two treatments observed (4.3(0.3) and 6.4(0.5) vs. 9.8(0.9), P = 0.001, 0.02, respectively).

CONCLUSION

These effects are likely to be attributable to the antioxidant properties of propofol, and suggest that propofol may have a protective role in disorders where free radical mediated injury promotes leucocyte-endothelium adhesive interactions.

The effects of propofol on neutrophil function, lipid peroxidation and inflammatory response during elective coronary artery bypass grafting in patients with impaired ventricular function

BACKGROUND

Coronary artery bypass grafting (CABG) with cardiopulmonary bypass elicits a potent reperfusion injury and inflammatory response, more intense in patients with impaired myocardial function. Propofol has antioxidant properties which may attenuate such a response.

METHODS

In total, 27 patients with impaired left ventricular function undergoing CABG were randomly allocated to receive either target-controlled infusion propofol (P) or saline (S) immediately before aortic cross-clamp release until 4 h after reperfusion. Troponin-I, Urinary 8-epi PGF-2alpha isoprostane, coronary sinus and systemic malondialdehyde concentrations, Interleukin-6 (IL-6), -8 and -10 concentrations and leucocytes function studies (neutrophil respiratory burst, phagocytosis, CD-11b and CD-18 expression) were measured.

RESULTS

Propofol decreased MDA coronary sinus concentration at 1, 3 and 5 min after reperfusion (P<0.01); 60 min after reperfusion a significant difference between the two groups in systemic MDA concentrations was also seen. IL-6 concentration increases were significantly greater in Group S than Group P, 4 h after reperfusion [1118 (1333) pg ml(-1) vs 228 (105) pg ml(-1), P<0.01]. Serum IL-8 concentrations did not increase significantly in either group. Compared with baseline values IL-10 concentrations decreased after reperfusion but the values were higher in the propofol group than in the control group [22 (16) vs 11 (4) pg ml(-1), P<0.05]. No difference in leucocyte function or urinary isoprostane concentrations was demonstrated.

CONCLUSION

Propofol attenuates free-radical-mediated lipid peroxidation and systemic inflammation in patients with impaired myocardial function undergoing CABG.

Elongated eccentric soft coronary plaque: major diagnostic pitfall on quantitative coronary angiography overpowered by computed tomography coronary angiography and intravascular ultrasound

We describe a significant left anterior descending coronary lesion in a patient with unstable angina pectoris. This lesion was erroneously underestimated using quantitative coronary angiography; however, CT coronary angiography correctly showed a significant, elongated, eccentric, soft plaque that was later confirmed by repeated quantitative coronary angiography with intravascular ultrasound. As showed, CT coronary angiography may offer a reliable non-invasive alternative to quantitative coronary angiography and intravascular ultrasound by enabling a true 3-D coronary lumenogram combined with plaque detection and characterization.